Accelerated FPGA repair through shifted scrubbing

Abstract

As critical systems make more and more use of high performance FPGAs, several reliability aspects of these devices come into play. Whenever SRAM-based FPGAs are used, upsets in the configuration memory become a major dependability threat, and must be removed as soon as possible. This is usually accomplished through a process called scrubbing. The traditional scrubbing technique, however, suffers from high energy costs and a long mean time to repair (MTTR). In this work we propose a novel approach to minimize these drawbacks through a triggered shifted scrubbing procedure. The proposed technique exploits the non-uniform distribution of critical bits in the configuration memory of the device to reduce the repair time. It provides an average MTTR reduction of 30% without any changes in the circuit implemented in the FPGA when compared to previous works.